Dostinex has been approved for the treatment of hyperprolactinemic disorders, either idiopathic or due to pituitary adenomas (tumors).

In a clinical trial involving approximately 450 subjects, Dostinex was compared with bromocriptine in treating hyperporlactinemia. In the eight-week, double blind trial, prolactin levels returned to normal in 77% of subjects treated with Dostinex (0.5mg twice weekly) compared to 59% of those treated with bromocriptine (2.5 mg twice-daily). Restoration of menses occurred in 77% of women treated with Dostinex, compared to 70% of those treated with bromocriptine.

Among subjects with galactorrhea (excessive breast milk discharge), the symptom disappeared in 73% of those treated with Dostinex, compared to 56% of 231 subjects taking bromocriptine.

Clinical studies also showed the safety profile of Dostinex compares favorably to bromocriptine. Two percent of 221 subjects taking Dostinex discontinued treatment due to side effects during the eight-week study, versus six percent of 231 subjects taking bromocriptine.

Nausea is the most common side effect of both drugs. During the eight-week, double-blinded portion of the trial, 29% of subjects experienced nausea with Dostinex compared with 43% of those taking bromocriptine.

Dostinex is contraindicated in subjects with uncontrolled hypertension or known hypersensitivity to ergot derivatives.

Hyperprolactinemia is usually caused by a benign tumor on the pituitary gland that results in excess production of prolactin, the hormone that controls lactation. Doctors treat from 70,000 to 100,000 patients with the condition each year, the vast majority of whom are women. It most commonly affects women between the ages of 20 to 50 and can cause cessation of menstruation, excessive milk discharge and infertility. In men, the condition can cause decreased libido and impotence.